Structure

ABSTRACT

This invention relates generally to cardboard structures, and particularly those for use in industrial pallets. The cardboard structure comprises layers of corrugated cardboard with corrugations running in different directions. This allows the resultant structure to take significant amount of stress in different directions. A pallet structure utilizing this cardboard also has feet formed from a single sheet of thin plastic material. It is free from sharp corners and stress risers and has ribs and ridges and valleys giving added strength to the resultant structure. A pallet having such feet has stringers made of a sandwich construction of corrugated cardboard covered by layers of corrugated cardboard having corrugations running in a direction perpendicular to the corrugations in the sandwich stringers.

United States Patent [72] Inventors Jacob Freid Detroit; Charles StanleyPorter. Pontiac, both of, Mich. 121] App]. No. 690,894 [22] Filed Dec.15,1967 [45] Patented July 6, 1971 [73] Assignee Atlas Pallet Corp.

Pontiac, Mich.

[541 STRUCTURE 9 Claims, 7 Drawing Figs.

[52] US. Cl 108/51, 108/58 [51] Int. Cl 565d 19/18 [50] Field of Search108/51- [56] References Cited UNITED STATES PATENTS 3,194,468 7/1965Baron 229/1.5 B 3,199,468 8/1965 Su1livan.... 108/53 3,237,834 3/1966Davis et a1. 229/l.5 B 2,706,099 4/1955 Whalley 108/53 2,951,669 9/1960Davidson 108/56 2,953,339 9/1960 Roshon 108/56 2,955,791 10/1960 George108/56 3,130,692 4/1964 Burk, et al.. 108/51 3,266,444 8/1966 Budd 4108/54 3,308,77l 3/1967 Wettlen.. 108/51 3,361,092 1/1968 Budd 108/58Primary Examiner-Casmir A. Nunberg Assistant Examiner-Glenn O. FinchAttorney-David A. Maxon ABSTRACT: This invention relates generally tocardboard structures, and particularly those for use in industrialpallets. The cardboard structure comprises layers of corrugatedcardboard with corrugations running in different directions. This allowsthe resultant structure to take significant amount of stress indifi'erent directions.

A pallet structure utilizing this cardboard also has feet formed from asingle sheet of thin plastic material, It is free from sharp comers andstress risers and has ribs and ridges and valleys giving added strengthto the resultant structure. A pallet having such feet has stringers madeof a sandwich construction of corrugated cardboard covered by layers ofcorrugated cardboard having corrugations running in a directionperpendicular to the corrugations in the sandwich stringers.

PATENTEH JUL 61% SHEET 2 OF 2 FIG4 FIG.6

DEP

STRUCTURE This invention relates generally to structures and portableplatforms or pallets used for storage and transport of merchandise andequipment. More particularly, this invention relates to pallets havingnestable oblong feet of thin sheets shaped like a flower pot and havingrippled sides free of sharp interior corners. These feet are reinforcedwith upwardly extending ribs extending from the bottom of the feet.These pallets have stringers formed from corrugated cardboard reinforcedwith sandwich construction of corrugated cardboard.

Pallets used for the transport and storage of merchandise and equipmentare ancient. However, pallets used in the past have not been entirelysatisfactory. It is desirable that pallets should be readily nestable sothat they can be stacked in large numbers in a relatively small amountof space. They should be lightweight and yet capable of carrying heavyloads to save costs in shipping. Pallets should be inexpensive toassemble and be made of inexpensive materials, A desirable feature ofpallet design is that variations in size, shape and strength of thepallet be readily obtained. Also, it should be designed to withstand andresist structural failure due to rough handling. This feature isparticularly important when a pallet is designed to be used fortransport by a fork lift truck. Where the feet of the pallet are madefrom a thin sheetlike material, the form of the feet should be free fromsharp interior angles to avoid concentration of stress in a small area.

It is an object of this invention to provide for pallet structure havingthese desirable features.

In the art of constructing and using corrugated cardboard structures, ithas become desirable to provide the strength of such structures insubstantial measure in more than one direction. For example, forincreased nestability, where it is desirable to have relatively thinstringers in pallets, it is necessary to have strength of stringers notonly to resist compressive vertical loads, but also to resist sidethrusts due to rough handling and transport by forklift trucks.

Also, where corrugated structures are used in making boxes forindustrial and consumer goods packaging, a box having strength in onedirection for one application cannot be used for another application.This is due to the geometry of a box being oriented differently fordifferent types of loading. In top loading, it is frequently desirableto have a box that has substantial strength to resist loads indirections perpendicular to the sides of the box. Thus, for top loading,corrugations in the sides run up and down or in a vertical direction.

However, in horizontal loading, forces are applied to the box that areboth parallel and perpendicular to the sides of the box. In thisapplication, boxes are frequently made with corrugations running in adirection parallel with the bottom of the box. This is often done at asacrifice of strength in the vertical direction.

It is an object of this invention to provide multiple layers ofcorrugated structure wherein the corrugations run in opposite directionsfor each succeeding layer.

It is another object of this invention to provide sandwich constructionof corrugated material wherein the corrugations vary in their directionfrom one layer of the sandwich to another.

Other objects of this invention will appear in the following descriptionand appended claims, referring to the accompanying drawings forming apart of the specification.

ON THE DRAWINGS FIG. I is a top plan view ofa foot used in the preferredem bodiment of this invention;

FIG. 2 is a transverse sectional view of the foot shown in FIG. 1;

FIG. 3 is a top plan view of the preferred embodiment of this invention;

FIG. 4 is a partial transverse sectional view of the apparatus shown inFIG. 3;

FIG. 5 is a partial sectional view of the apparatus shown in FIGS. 3 and4;

FIG. 6 is a partial plan view of sandwich construction of corrugatedmaterial wherein the corrugations run in opposite directions indifferent layers;

and, FIG. 7 is a partial sectional view of a wall of multiple layercorrugated structure wherein corrugations run in different directionsfrom one layer to another.

Before explaining the present invention in detail, it is to beunderstood that the invention is not limited in its application as todetails of construction and arrangement of parts illustrated in theaccompanying drawings, since the invention is capable of otherembodiments and of being practiced carried out in various ways. Also, itis to be understood that the phraseology and terminology is for thepurpose of description and not limitation.

AS SHOWN ON THE DRAWINGS In FIG. ll, there is shown a foot used in thepreferred embodiment of this invention. This foot is made ofa thin sheetof material. The preferred material is a plastic such as polyethylene.The sheet of material is formed into a shape resembling a casserole dishor oblong flower pot 10. The foot has a flange 12 having a flat surfaceand being at the top of the foot. The bottom portion 14 of the foot isgenerally flat and is free from holes, apertures or openings. The sides16 of the foot are slanted. The sides 16 have ripples or ridges l8 andvalleys 20. The sides of the foot are free from any sharp interiorangles. The ridges 18 and valleys 20 form a continuous smooth roundedside. The flange 12 and the bottom portion 14 meet the sides 16 of thefoot in rounds having a relatively smaller arc than the ridges l8 andthe valleys 20. However, the flange l2 and the bottom 14 do not meet thesides 16 with any sharp interior angles or corners. The sides or walls16 that meet in places such as the sector 24 do so with rounds havingarcs that are smaller than the ridges l8 and valleys 20. However, thesearcs are not so small as to constitute sharp corners or sharp interiorangles. The ridges l8, valleys 20 and sectors 24 form a continuous wallof the foot free of sharp corners and geometry that could cause stressconcentrations.

The foot 10 is reinforced by ribs 26 and 28 that intersect one anotherand join the walls or sides 16 of the foot. These ribs extend in anupward vertical direction from the bottom or floor portion 14 of thefoot. The height of these ribs is of the same order of magnitude as thethickness of stringers of the pallet to which the foot is attached. Inthis manner a significant increase in the structural strength andload-carrying capacity of the foot is achieved without reducing orinhibiting or preventing a nestable character ofa pallet using thisfoot.

As shown in FIG. 1, the preferred embodiment of this foot has the footshaped in an oblong or parallel pipedlike configuration. With thisshape, maximum structural load-carrying capacity can be achieved in aminimum amount of space when the pallet is designed to be used fortransport by a forklift truck.

In FIG. 3 there is a pallet construction in the preferred embodiment ofthis invention. The pallet 50 comprises feet 52 of the type shown inFIG. 1. Nine of these feet are shown in a 3X3 configuration. They arespaced a uniform distance apart.

The flanges 54 of each of the feet are inserted to rest on top of abottom corrugated sheet 56. This insertion can be secured by glue or byrivets or by other appropriate means. It is possible to relay simply onthe pressure of insertion of this flange above this cardboard sheet orcover without additional securing means such as glue or rivets.

Placed on top of the flanges and extending between the feet arestringers 58 of sandwich material. These stringers are preferably madeof a corrugated sandwich structure in which the corrugations run in avertical direction. In an alternative embodiment of this invention, woodor other appropriate load-carrying means can be substituted. forcorrugated cardboard material. However, because of its light weight andloadcarrying properties, corrugated sandwich construction is preferredfor the stringers.

On top of the corrugated sandwich construction is placed a cover 60 alsomade of corrugated cardboard material, being a single layer in thepreferred embodiment. In an alternative embodiment of this invention, amultilayered structure of corrugated covers, where the corrugations runin opposite directions, can be used. This type of construction is shownin FIG. 7.

In its preferred embodiment, this invention shows flexibility in thedesign of pallets by the ability to vary the amount of strength neededin the pallet. This can be done readily by varying the amount ofsandwich corrugated cardboard material used as stringers. For arelatively inexpensive pallet and for lesser weight, where a great dealof strength is not required, a minimum amount of corrugated sandwichmaterial can be used to form a framelike structure with rather narrowwidths of sandwich material. For heavier construction requiring greaterload-carrying capacity, a plan view of a transverse section of thepallet would show sandwich construction throughout the pallet with theexception of the areas penetrated by the dish portion of the feet. Forextremely light pallets with very little weight being placed upon them,the sandwich construction can be eliminated and reliance can be made onstringers composed entirely of multiple layers of cover sheets ofcorrugated cardboard where corrugations run in opposite directions. Thisform of construction is shown in FIG. 7.

In an alternative embodiment of this invention, corrugated cardboardstructures can be provided with substantial strength in severaldirections by using sandwich construction of corrugated cardboard wherecorrugations run in different directions, as shown in FIG. 6.

In a further alternative embodiment of this invention, corrugatedcardboard structures can be constructed that will withstand forces fromseveral directions by using stringers composed of multiple layers ofcover sheets wherein the corrugations run in opposite directions.

Another embodiment of this invention lies in a form for a corrugatedcardboard box. This form has several layers of corrugated cardboard. Thecorrugations in different layers run in different directions.

From the foregoing description it can be appreciated that a novelconstruction of pallets and corrugated cardboard structures has beenprovided to withstand and carry structural loads varying from the lightto the heavy with considerable saving in weight and cost.

lclaim:

1. In a pallet, the improvements comprising:

Feet of thin sheetlike material shaped into load supporting structure;

said feet having downwardly sloping sides forming one con tinuousrippled wall; said feet having sides and a bottom free of apertures andforming one continuous interior surface and one continuous exteriorsurface where both such surfaces are free of sharp interior angles andfree of sharp interior corners and free of arcs having a radius of anorder of magnitude less than the order of magnitude of the thickness ofsaid sides and bottom; said feet having a flange surrounding andattached to and integral with said continuous wall; whereby saidcontinuous wall has both interior and exterior surfaces that are bothfree of stress-rising, discontinuous and sharp shapes between the ridgesand valleys thereof and between said walls and said bottom and saidflanges. 2. The apparatus of claim 1 wherein said feet have flanges thatare pressed between layers of corrugated cardboard stringers;

said flange being substantially parallel to said layers. 3. Theapparatus of claim 1 wherein said feet have flanges that are secured toa cover sheet of corrugated cardboard in the stringers;

said flange being substantially parallel to said cover sheet. 4. Theapparatus of claim 1 wherein each of said feet are surrounded by aflange integral with its sides, said flange being free of apertures.

5. The apparatus of claim 1 and stringers of corrugated cardboard.

6. In the apparatus ofclaim l:

stringers of corrugated cardboard;

and additional stringers having material chosen from the groupconsisting of wood, metal, and plastic.

7. The apparatus of claim 5 wherein said stringers are reinforced bysandwich construction of corrugated cardboard in the stringers;

said sandwich construction comprising a pair of contiguous layers ofcorrugated cardboard with cover sheets therebetween;

the corrugations of one of said layers being substantially perpendicularto the corrugations in the other of said layers;

wherein loads are applied on the pallet in a direction parallel to thedirection of corrugations in said first-mentioned layer.

8. In the apparatus of claim 1, ribs upwardly extendingfrom said bottom;

said ribs being contiguous and substantially perpendicular to saidbottom;

whereby said feet have substantially greater rigidity and strength insupporting loads on the pallet.

9. The apparatus of claim 8 wherein said ribs have a height having thesame order of magnitude as the thickness of the stringers of saidpallet.

1. In a pallet, the improvements comprising: Feet of thin sheetlikematerial shaped into load supporting structure; said feet havingdownwardly sloping sides forming one continuous rippled wall; said feethaving sides and a bottom free of apertures and forming one continuousinterior surface and one continuous exterior surface where both suchsurfaces are free of sharp interior angles and free of sharp interiorcorners and free of arcs having a radius of an order of magnitude lessthan the order of magnitude of the thickness of said sides and bottom;said feet having a flange surrounding and attached to and integral withsaid continuous wall; whereby said continuous wall has both interior andexterior surfaces that are both free of stress-rising, discontinuous andsharp shapes between the ridges and valleys thereof and between saidwalls and said bottom and said flanges.
 2. The apparatus of claim 1wherein said feet have flanges that are pressed between layers ofcorrugated cardboard stringers; said flange being substantially parallelto said layers.
 3. The apparatus of claim 1 wherein said feet haveflanges that are secured to a cover sheet of corrugated cardboard in thestringers; said flange being substantially parallel to said cover sheet.4. The apparatus of claim 1 wherein each of said feet are surrounded bya flange integral with its sides, said flange being free of apertures.5. The apparatus of claim 1 and stringers of corrugated cardboard.
 6. Inthe apparatus of claim 1: stringers of corrugated cardboard; andadditional stringers having material chosen from the group consisting ofwood, metal, and plastic.
 7. The apparatus of claim 5 wherein saidstringers are reinforced by sandwich construction of corrugatedcardboard in the stringers; said sandwich construction comprising a pairof contiguous layers of corrugated cardboard with cover sheetstherebetween; the corrugations of one of said layers being substantiallyperpendicular to the corrugations in the other of said layers; whereinloads are applied on the pallet in a direction parallel to the directionof corrugations in said first-mentioned layer.
 8. In the apparatus ofclaim 1, ribs upwardly extending from said bottom; said ribs beingcontiguous and substantially perpendicular to said bottom; whereby saidfeet have substantially greater rigidity and strength in supportingloads on the pallet.
 9. The apparatus of claim 8 wherein said ribs havea height having the same order of magnitude as the thickness of thestringers of said pallet.